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Spectrally intense terahertz source based on triangular Selenium.

Shalaby M, Hauri CP - Sci Rep (2015)

Bottom Line: The intensity of a nonlinear terahertz (THz) source is primarily given by its spectral density.In this letter, we introduce triangular Selinium (Se) as a novel THz emitter and show numerically its superior properties to the currently used crystals for intense THz generation.The excellent phase matching enables the applicability of elongated Se crystals which results in very high spectral flatness and broad THz bandwidth (0.5-3.5 THz), high conversion efficiency and THz pulse energy.The spectral THz density produced by optical rectification in Selenium exceeds those from contemporary crystal-based THz sources.

View Article: PubMed Central - PubMed

Affiliation: 1] SwissFEL, Paul Scherrer Institute, 5232 Villigen PSI, Switzerland [2] Physics Department, ETH Zurich, 8093 Zurich, Switzerland.

ABSTRACT
The intensity of a nonlinear terahertz (THz) source is primarily given by its spectral density. In this letter, we introduce triangular Selinium (Se) as a novel THz emitter and show numerically its superior properties to the currently used crystals for intense THz generation. The excellent phase matching enables the applicability of elongated Se crystals which results in very high spectral flatness and broad THz bandwidth (0.5-3.5 THz), high conversion efficiency and THz pulse energy.The spectral THz density produced by optical rectification in Selenium exceeds those from contemporary crystal-based THz sources.

No MeSH data available.


The buildup of the temporal profiles along the propagation direction in (a) DAST and (b) Se crystals.While the single-cycle pulse maintains it temporal shape (except for a shift of the absolute phase) throughout a thick crystal (up to 2 mm), the THz pulse produced in DAST turns from a single-cycle (d = 0.1 mm) into a multi-cycle pulse (d = 0.8 mm) while propagating through the crystal. The pulses are arbitrarily time-delayed for clarity.
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f3: The buildup of the temporal profiles along the propagation direction in (a) DAST and (b) Se crystals.While the single-cycle pulse maintains it temporal shape (except for a shift of the absolute phase) throughout a thick crystal (up to 2 mm), the THz pulse produced in DAST turns from a single-cycle (d = 0.1 mm) into a multi-cycle pulse (d = 0.8 mm) while propagating through the crystal. The pulses are arbitrarily time-delayed for clarity.

Mentions: Finally, we look at the corresponding pulse time profile. In some applications such as magnetization dynamics36, the nonlinear response strongly depends on the time profile of the THz pulse. Figure 3 shows a coherent buildup of the pulse amplitude over d in Se. Except for a cumulative carrier envelope phase, the output electric fields at 0.4 and 2 mm maintain the original shape while the field strength steadily increases, apart from an additional phase shift due to accumulated material dispersion in the crystal. In contrast, DAST offers an inferior performance as the time profile strongly changes with d and is greatly dispersed. This originates from both the short Leff and the strong refractive index dispersion (driven by the 1.1 THz resonance absorption, Fig. 1(a)).


Spectrally intense terahertz source based on triangular Selenium.

Shalaby M, Hauri CP - Sci Rep (2015)

The buildup of the temporal profiles along the propagation direction in (a) DAST and (b) Se crystals.While the single-cycle pulse maintains it temporal shape (except for a shift of the absolute phase) throughout a thick crystal (up to 2 mm), the THz pulse produced in DAST turns from a single-cycle (d = 0.1 mm) into a multi-cycle pulse (d = 0.8 mm) while propagating through the crystal. The pulses are arbitrarily time-delayed for clarity.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4307012&req=5

f3: The buildup of the temporal profiles along the propagation direction in (a) DAST and (b) Se crystals.While the single-cycle pulse maintains it temporal shape (except for a shift of the absolute phase) throughout a thick crystal (up to 2 mm), the THz pulse produced in DAST turns from a single-cycle (d = 0.1 mm) into a multi-cycle pulse (d = 0.8 mm) while propagating through the crystal. The pulses are arbitrarily time-delayed for clarity.
Mentions: Finally, we look at the corresponding pulse time profile. In some applications such as magnetization dynamics36, the nonlinear response strongly depends on the time profile of the THz pulse. Figure 3 shows a coherent buildup of the pulse amplitude over d in Se. Except for a cumulative carrier envelope phase, the output electric fields at 0.4 and 2 mm maintain the original shape while the field strength steadily increases, apart from an additional phase shift due to accumulated material dispersion in the crystal. In contrast, DAST offers an inferior performance as the time profile strongly changes with d and is greatly dispersed. This originates from both the short Leff and the strong refractive index dispersion (driven by the 1.1 THz resonance absorption, Fig. 1(a)).

Bottom Line: The intensity of a nonlinear terahertz (THz) source is primarily given by its spectral density.In this letter, we introduce triangular Selinium (Se) as a novel THz emitter and show numerically its superior properties to the currently used crystals for intense THz generation.The excellent phase matching enables the applicability of elongated Se crystals which results in very high spectral flatness and broad THz bandwidth (0.5-3.5 THz), high conversion efficiency and THz pulse energy.The spectral THz density produced by optical rectification in Selenium exceeds those from contemporary crystal-based THz sources.

View Article: PubMed Central - PubMed

Affiliation: 1] SwissFEL, Paul Scherrer Institute, 5232 Villigen PSI, Switzerland [2] Physics Department, ETH Zurich, 8093 Zurich, Switzerland.

ABSTRACT
The intensity of a nonlinear terahertz (THz) source is primarily given by its spectral density. In this letter, we introduce triangular Selinium (Se) as a novel THz emitter and show numerically its superior properties to the currently used crystals for intense THz generation. The excellent phase matching enables the applicability of elongated Se crystals which results in very high spectral flatness and broad THz bandwidth (0.5-3.5 THz), high conversion efficiency and THz pulse energy.The spectral THz density produced by optical rectification in Selenium exceeds those from contemporary crystal-based THz sources.

No MeSH data available.